Optical transport network (OTN) is available as one of the optical transmission techniques. OTN is being standardized by International Telecommunication Union-Telecommunication sector (ITU-T) and Institute of Electrical and Electronic Engineers (IEEE). OTN is described in ITU-T G.709/Y. 1331 (12/2009), “Interfaces for the Optical Transport Network (OTN)”.
Reed-Solomon code RS (255, 239) is standardized in an error correction system of OTUk(V) layer of OTN. The error correction scheme of RS (255, 239) is described in ITU-T G.975(10/2000), “Forward error correction for submarine systems.”
As communication traffic volume increases, high-speed, long-distance, and low-cost communication designs of networks are promoted. Performance increase in the error correction technique is desired. A technique described in ITU-T G. 975.1 provides an improved mapping method by combining types of and concatenations of codes and is expected to outperform RS (255, 239). OTUk stands for “optical channel transport unit-k”.
One error correction apparatus estimates an error location of a second data packet received subsequent to a first data packet, based on error correction information of the first data packet having undergone an error correction operation. One decoder apparatus partitions received data into block segments and repeats on each block segment a coding stop determination operation as to whether to stop decoding on the block segment, and determines based on the results of the coding stop determination operation that a decoding operation of the received data is to stop. Another error correction decoder apparatus repeats convolutional decoding in a first decoder using decoding results of a second decoder as syndrome-based prior probability series.
Related art is disclosed in Japanese Laid-open Patent Publication No. 2004-215240, Japanese Laid-open Patent Publication No. 2007-142622, and Japanese Laid-open Patent Publication No. 2009-200732.